| MEASUREMENT PROPERTIES | |
| Limitations | <5 European languages (English) |
| Observations |
The validation of the TOL-AR-18 was carried out with a cross-sectional, observational, multi-centre study with consecutive inclusion of patients with RA from 6 Rheumatology departments from Spain. |
| 1. RELIABILITY | |
| A. Internal Consistency | Tested |
| Cronbach's (Describe) |
Cronbach’s alpha values were greater than 0.95 for each item, which indicates that all items were very inter-related. Correlation between each item and overall score was greater than 0.3. |
| B. Reliability intraobserver or test-retest | Not Tested |
| Continuous scores: intraclass correlation coefficient (ICC) Dichotomus: Cohen kappa (Describe) |
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| C. Reliability interobserver or Measurement error | Not Tested |
| Standard error of measurement (SEM), smallest detectable change (SDC) or Limits of agreement (LoA) (Describe) |
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| 2. VALIDITY | |
| A. Content validity: face validity | Tested |
| Expert opinion (relevance and comprehensiveness) (Describe) |
The TOL-AR-18 questionnaire was designed using a standardized methodology for development of patient-centred measures, following a bibliographic review, a focus group with rheumatologists, and interviews with patients. |
| B. Construct Validity: Structural validity |
Not Tested |
| Hypotheses-testing | Tested |
| Cross-cultural validity | Not Tested |
| Brief Description | |
| C. Criterion validity | Tested |
| Comparison with a 'gold standard' Continuous scores: correlations, ROC curves Dichotomus: Sensitivity & Specificity (Describe) |
Spearman’s correlation coefficient (Rho) between TOL-AR-18 dimensions and ARthritis Treatment Satisfaction questionnaire (ARTS) questionnaire scores (items 9, 10 and tolerability dimension) was calculated. The dimensions of the questionnaire TOL-AR-18 had an inverse and low-moderate correlation with ARTS questionnaire (item 9 and item 10). Item 10 of ARTS had higher correlation coefficients with the dimensions of the TOL-AR-18 than item 9: between 0.21 and 0.38 and between 0.09 and 0.34 respectively. ‘General health status’ and ‘psychological/cognitive’ dimensions of TOL-AR-18 showed the highest correlation coefficients with tolerability dimension of the ARTS while ‘energy-vitality’ showed the lowest. In addition, in the analysis of answers to the question about general health status, differences in the ‘daily activity’ and ‘psychological–cognitive’ dimensions and overall score for the TOL-AR-18 were found to be statistically significant (P = .008; 0.024; 0.041). |